And you think the next generation of bombers won't improve enough that the F22s would have a hard time? Fighters and bombers have each evolved at the same rate. The existing ratio still has not changed. F-22s would still have a hard time taking down B-1s with its speed and have a hard time finding the B-2s with all its countermeasures. The F-22 has to find the bombers first these days, something not done easily enough.
Whatever improvements fighter tech gets, you can be sure bombers will not be far behind. This is so because the bombers have to survive whatever current dominant fighter can dish out.
The F22 is 44% faster than the B1 without afterburner, and 60% faster on full thrust. It is also far stealthier than the B2. This is hardly surprising, considering it's a newer generation of aircraft (and much much smaller than the B2). The B3 won't come online until at least 2018. Any unescorted group of bombers intercepted by fighters would be obliterated with room to spare. Modern combat doctrine revolves around either not exposing the bombers to risk in the first place, or escorting them.
And Defensive technology does NOT always keep up. It's far easier to destroy than to protect. No amount of armour plating could practically protect a battleship against large bombs dropped from high altitude. No missile defense program could hope to ward off an all out ICBM attack - decoy warheads, evasive manoeuvring, multiple warheads make a shield pointless against all but the smallest scale launches.
So it's neither clear that technology keeps up, nor that fighters can't have higher kill ratios against undefended bombers. But even if I conceded these points, the argument "Historically fighters have not had high kill ratios" is not proof against "In the far future, fighters can have high kill ratios".
Furthermore, you are considering that the fighters must kill every single bomber and therefore individually have a high kill ratio, when in fact the kill ratio is irrellevant so long as the bomber formation is disrupted to such an extent that it ceases to be an effective formation and has to abort, not necessarily through casualties sustained, but due to an impossibility of regrouping into an effective formation and out-of-formation bombers posing no threat to capital ships. So long as the fighters achieve that, they need not kill a single bomber, yet could still be effective at disrupting multiple squadrons.
But
WHY are we thinking about modifying fighters? Fighters have an interceptor role, and an escort role. In BFG, they do fine in an interception role, but
poorly in an escort role - there's
no benefit to escorting assault boats ever, and
it's only worth escorting bombers if the target has more than two turrets thanks to a clunky turret suppression that is also under review.
What have the suggestions so far been?
#1. Increase the Kill Ratio of Fighters against assault boats and bombers to at least 2:1.
#2. A Dogfight Mechanic.
#3. An Attrition Mechanic, with limited AC that must be protected.
#4. Do nothing.
Why is increasing the kill ratio far and away the best suggested option? Because option 4 leaves us with a deeply unsatisfying situation, whilst the Dogfight Mechanic and Attrition Mechanic must by their very nature both slow down the game (they have to - there's more to work out), and increase the complexity of the rules (they have to - they're adding a mechanic that doesn't exist).
Conversly, increasing the kill ratio takes no extra game time (simply remove extra markers!), and is a minor modification to an existing mechanic, and still addresses the core issue - provide a strong incentive to escort waves of bombers or assault boats. It's possible that someone could come up with a better idea that addresses this issue, but given how elegant and simple the "Increase the Kill Ratio" option is, I highly doubt it.